Some females will make nests, I've even hard several stories about females dropping eggs, making nests, and tending to those eggs all on their own.....but I'm pretty sure that your guy is male from what I can see of the ventral length in that picture. I'd need a closer up side profile pic(flaring would be awesome)to know for sure though ;)

I have the same issue, my father told me the fish was female (I pressume he got that information from the store), anyway it has made many bubble nests and is EXTREMELY aggresive... It looks very similar to your fish so I am thinking it's a plakat male. The above photo is my fish.

Last edited by Artarmon; 01-28-2010 at 04:24 AM.
Reason: (adding a photo)